In some surgical procedures (e.g. tumor resection) a mass of biological material is removed as part of a therapy plan. The removed mass is analyzed to determine whether margins are clean (i.e. free of abnormal cells). In cases where margins are not clean, removal of additional tissue is indicated.
U.S. Pat. No. 6,109,270 describes a measurement concept with a multi-modality instrument for tissue identification in real-time neuro-surgical applications. U.S. Pat. Nos. 6,813,515; 7,082,325 and 7,184,824 U.S. Patent Applications published as 20070260156; 20070255169; 20070179397; 20070032747; 20070032739; 20060264738; 20060253107; 20050021019; 20030187366 and 20030138378 describe tools systems and methods useful in assessing tissue type and/or identifying tumor margins. U.S. Pat. No. 5,615,132 describes a method and apparatus for determining position and orientation of a moveable object using accelerometers.
U.S. Pat. No. 6,833,814 describes an intrabody navigation system for medical applications in which three planar antennas that at least partly overlap are used to transmit electromagnetic radiation simultaneously. PCT application IL 2007/001539 describes apparatus for analysis of a substrate.
US 2004/0243148 by Wasielewski, which is fully incorporated herein by reference, includes a review of source and sourceless sensors including examples of commercially available products in paragraphs 0087-0103 as well as reference to earlier US patent applications 2002/0180306 and 2002/0104376 which are each fully incorporated herein by reference.
Ascension Technology Corp. (Burlington Vt., USA) markets a guide for localizing medical instruments with 3D magnetic tracking as “3D Guidance™ Medsafe”.
Traxtal Inc. (Toronto, Ontario, Canada) markets probes suitable for registration and general navigation purposes and skin mounted patches suitable for tracking a point on a patient.
Northern Digital hie. (NDI; Waterloo, Ontario Canada) markets electromagnetic tracking components (Aurora®) and optical tracking components (Optitrak® and/or Polaris®). Crossbow Technology hie. (San Jose, Calif., USA) markets a wide range of sensors which rely on accelerometry, angular rate measurement (gyros), magnetometry and GPS.